4.48 ONISCID &. 
ISOPODA. ONISCIDA. 
NORMALIA. 
Genus—PHILOSCIA. (Latreille.) 
ZIA. (Koch.) 
Generic character. Ovate, sub-depressed. Cephalon rounded, 
not lobed. Inner antenne minute, conical. Outer antennee 
with cylindric joints, eight-jointed. Coxe of sixth segment 
of pleon obsolete; first to fifth, narrow, linear. Uropoda 
entirely exserted; basal portion quadrilateral, transverse. 
Rami elongate, pointed at tip; outer terminating in a bundle 
of setee; inner more slender, and extending beyond the 
middle of the outer ramus. 
Ir is a curious circumstance that the animals of this 
genus, common as they are, and well described by 
Latreille and Zaddach, should have been unknown to 
Brandt, Lereboullet, and Milne Edwards, who have 
affirmed that the genus ought to be reunited to Oniscus, 
whereas it is in fact more nearly allied in several respects 
to Ligia. The typical species appears to have been 
figured by Koch under the name of Ligia melanocephala, 
which in his generic table he subsequently altered into 
the generic name of Zia, giving, however, fifteen joints 
to the antennz, the flagellum being represented as com- 
posed of ten articulations. 
The species are glossy, with the body flattened, and 
the head destitute of lateral or frontal lobes. ‘‘ The 
inferior border of the frontal ring of the head is nearly 
straight across; the transverse suture well marked, 
nearly on a level with the superior margin of the ex- 
ternal antennz, its superior margin curved, raised, and 
passing slightly beyond the frontal line of the cephalic 
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